My favorite topic. And a no brainer decision.
Chill out on new classes for a couple expansions and instead introduce new specs to current classes.
Shaman Tank is an obvious #1, but there are others. Evoker could have a tank spec. Mage could have a healer spec. Rogue could have a ranged spec. DH a ranged spec. Etc.
An Earth-Focused Shaman Tank spec writes itself too. Shield use. Earth based DR. Water based self-healing. Totem/Elemental support.
One day…one day.